It has been known that one or a plurality of air bags is provided in motor vehicles to protect occupants in case of the accidents of the vehicles. As air bags, there have been known various types such as so-called air bags for drivers that inflate in the vicinity of the steering wheels of automobiles to protect the drivers, side curtain air bags that deploy downward inside the windows of automobiles to protect occupants during lateral impacts on vehicles, lateral turning, or overturning accidents, and side air bags that deploy between occupants and side panels to protect the occupants during lateral impacts on vehicles. The present invention relates to a side air bag device installed in a vehicle seat and an occupant protection device having the side air bag device.
A side air bag device described in Japanese Patent Application Laid-Open No. 2009-023494 has a main air bag and a subsidiary air bag. Further, the subsidiary air bag inflates and deploys prior to the main air bag to restrain an occupant at an early stage. Other than the invention described in the above-mentioned reference, side air bag devices each having a subsidiary air bag in addition to a main air bag have been proposed. It has been strongly requested that such side air bag devices be reduced in size. Moreover, it has been that damage argument protection be provided not only by a main air bag but also by a subsidiary air bag.